I have a 2001 115 hp evinrude. It is on a 16'Larson Flyer and use it mostly for skiing. It pulls an adult skier out of the hole pretty good, but can only get about 45 MPH at WOT( the dealer told me it should get around 55MPH). It has a 3 blade 14" 17 pitch aluminum prop on it. I recently saw a...